Tomato Hornworms: 5 Steps to Find the Pests Hiding in Plain Sight

You walk out to check your tomatoes, coffee in hand, and something looks wrong. Yesterday, those vines were full of healthy green leaves. Today, several branches are practically bare.

And the most annoying part? Whatever ate them is nowhere to be seen.

There’s a good chance you’re dealing with tomato hornworms. These chunky green caterpillars can strip a surprising amount of foliage from a tomato plant, yet they’re so well camouflaged that you can stare straight at one and miss it.

Fortunately, you can usually get rid of tomato hornworms without harsh chemical sprays. Once you know what to look for, finding them becomes much easier. I’ll show you where they hide, how to follow the clues they leave behind, and what to do when you finally spot one.

What You’re Dealing With (And Why the Damage Happens So Fast)

Tomato hornworms are large green caterpillars that feed on tomatoes and other members of the nightshade family.

They’re one of those garden pests that make you wonder how something so big managed to stay hidden for so long.

Tomato Hornworm vs. Tobacco Hornworm

You might actually have one of two closely related caterpillars munching through your tomato plants.

Tomato hornworms (Manduca quinquemaculata) have eight white V-shaped markings along their sides and a dark horn at the rear.

Tobacco hornworms (Manduca sexta) have seven diagonal white stripes along their sides and usually a reddish horn.

Both can grow to around four inches long, and neither is particularly fussy about sticking to tomatoes. Peppers and eggplants are fair game, too.

For most home gardeners, there’s no need to worry too much about which one you’ve found. They cause similar damage, and you deal with them the same way.

Why Hornworms Seem to Eat Tomato Plants Overnight

Small hornworms don’t attract much attention. They take little bites here and there, and the damage is easy to overlook.

Then they grow.

Once hornworms reach their final growth stages, their appetite increases dramatically. A large caterpillar can strip a leafy branch surprisingly quickly. Put a few on a young tomato plant, and you can have a real mess in just a couple of days.

Their coloring doesn’t help matters. A hornworm resting against a tomato stem looks remarkably like part of the plant. By the time you notice those bare branches, it may have been feeding for days.

3 Telltale Signs of Tomato Hornworm Damage

When hornworms are the likely suspects, these are the clues worth checking first:

1. Bare stems near the top of the plant. Leaves have disappeared, leaving behind stripped leaf stalks or central veins.
2. Large, irregular holes in leaves or fruit. Hornworms sometimes chew into green or ripening tomatoes.
3. Green, dark green, or black droppings below damaged branches. These small pellets, called frass, can be easier to find than the caterpillar itself.

Unlike many tomato diseases, hornworms actually remove leaf tissue. If your leaves are curling, yellowing, or developing spots without chunks missing, you may be dealing with something else.

One more thing: that wicked-looking horn isn’t a stinger. Hornworms are generally harmless to handle, even if they look a little intimidating.

What You’ll Need to Get Rid of Tomato Hornworms

You don’t need fancy equipment or an entire afternoon to deal with a few hornworms.

For a small garden, a bucket and a careful look through your tomato plants will often do the job.

Your Simple Hornworm-Removal Kit

Grab these before heading outside:

• A small bucket of soapy water or a sealable container
• Gardening gloves, if you’d rather not touch caterpillars
• A flashlight or UV blacklight for checking plants after dark
• Pruners, in case you need to move a hornworm carrying beneficial wasp cocoons

A blacklight is useful, but don’t feel you need to buy one just to deal with a couple of caterpillars. Once you know their hiding places, you can find plenty of hornworms in daylight.

Know When to Remove a Hornworm and When to Leave It

Before pulling a hornworm off your tomato plant, take a quick look at its back.

A plain green hornworm is usually one to remove. But if it’s covered in tiny white, rice-shaped cocoons, leave it alone if possible.

Those cocoons belong to beneficial parasitic wasps. They develop at the expense of the hornworm and can help keep future populations under control.

We’ll look at that more closely in Phase 5. For now, just remember to check before you pick.

How to Find and Remove Tomato Hornworms in 5 Steps

You don’t have to inspect every leaf on every tomato plant. Start with the damage, follow the clues, and work your way toward the caterpillar.

Here’s the quickest way to tackle the problem.

Phase 1: Find the Freshest Hornworm Damage

Don’t search the entire tomato plant just yet. Start where the leaves are disappearing.

Check the Upper Branches

Hornworms often feed on tender new growth.

Look for missing leaflets, bare leaf stalks, and large sections of chewed foliage. Follow the damaged branch inward toward the main stem.

The caterpillar may be resting close to where it last fed.

Search Their Favorite Hiding Places

Under leaves: Lift large leaves gently and inspect their undersides.

Along stems: Look for an unusually thick, smooth green shape that doesn’t quite belong.

At branch junctions: Check where leaves and stems meet, particularly in shaded areas.

A large hornworm can look so much like a tomato stem that it’s easy to overlook.

What to Watch For

Freshly chewed stems often have pale green, slightly moist edges.

Still can’t find it? Move on to Step 2.

Phase 2: Follow the Hornworm Droppings

Hornworms are masters of camouflage, but their droppings often give away their hiding places.

Find the Frass

Look on lower tomato leaves and the soil beneath damaged branches.

Fresh frass: Often green and sometimes slightly moist.

Older frass: Usually dark green, brown, or black, with a drier appearance.

The pellets may have noticeable ridges, especially when produced by larger caterpillars.

This color distinction can be a useful clue. Fresh green pellets often suggest recent feeding, while darkened droppings may indicate older activity. However, moisture and other conditions can affect their appearance, so check the surrounding foliage too.

Follow the Trail Upward

First: Find the freshest-looking droppings.

Next: Inspect the stems and leaves above them.

Then: Work outward along nearby branches if you don’t spot the caterpillar.

Droppings can bounce off leaves as they fall, so the hornworm won’t always be directly overhead.

Your Hornworm Detective Trail

Example: The Mystery of the Bare Branch

Phase 3: Remove Tomato Hornworms by Hand

Found a hornworm? You’re already most of the way there.

For a few caterpillars, hand-picking is usually the simplest and most effective approach.

Check Before You Pick

Take a quick look at the caterpillar’s back.

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